The Tor Browser: comparison mobile/android/thirdparty/ch/boye/httpclientandroidlib/impl/DefaultConnectionReuseStrategy.java

--1:000000000000
+:016cd85e3cd3
+/*
+* ====================================================================
+* Licensed to the Apache Software Foundation (ASF) under one
+* or more contributor license agreements.  See the NOTICE file
+* distributed with this work for additional information
+* regarding copyright ownership.  The ASF licenses this file
+* to you under the Apache License, Version 2.0 (the
+* "License"); you may not use this file except in compliance
+* with the License.  You may obtain a copy of the License at
+*
+*   http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing,
+* software distributed under the License is distributed on an
+* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+* KIND, either express or implied.  See the License for the
+* specific language governing permissions and limitations
+* under the License.
+* ====================================================================
+*
+* This software consists of voluntary contributions made by many
+* individuals on behalf of the Apache Software Foundation.  For more
+* information on the Apache Software Foundation, please see
+* <http://www.apache.org/>.
+*
+*/
+package ch.boye.httpclientandroidlib.impl;
+import ch.boye.httpclientandroidlib.ConnectionReuseStrategy;
+import ch.boye.httpclientandroidlib.HttpConnection;
+import ch.boye.httpclientandroidlib.HeaderIterator;
+import ch.boye.httpclientandroidlib.HttpEntity;
+import ch.boye.httpclientandroidlib.HttpResponse;
+import ch.boye.httpclientandroidlib.HttpVersion;
+import ch.boye.httpclientandroidlib.ParseException;
+import ch.boye.httpclientandroidlib.ProtocolVersion;
+import ch.boye.httpclientandroidlib.protocol.HTTP;
+import ch.boye.httpclientandroidlib.protocol.HttpContext;
+import ch.boye.httpclientandroidlib.protocol.ExecutionContext;
+import ch.boye.httpclientandroidlib.TokenIterator;
+import ch.boye.httpclientandroidlib.message.BasicTokenIterator;
+/**
+* Default implementation of a strategy deciding about connection re-use.
+* The default implementation first checks some basics, for example
+* whether the connection is still open or whether the end of the
+* request entity can be determined without closing the connection.
+* If these checks pass, the tokens in the <code>Connection</code> header will
+* be examined. In the absence of a <code>Connection</code> header, the
+* non-standard but commonly used <code>Proxy-Connection</code> header takes
+* it's role. A token <code>close</code> indicates that the connection cannot
+* be reused. If there is no such token, a token <code>keep-alive</code>
+* indicates that the connection should be re-used. If neither token is found,
+* or if there are no <code>Connection</code> headers, the default policy for
+* the HTTP version is applied. Since <code>HTTP/1.1</code>, connections are
+* re-used by default. Up until <code>HTTP/1.0</code>, connections are not
+* re-used by default.
+*
+* @since 4.0
+*/
+public class DefaultConnectionReuseStrategy implements ConnectionReuseStrategy {
+public DefaultConnectionReuseStrategy() {
+super();
+}
+// see interface ConnectionReuseStrategy
+public boolean keepAlive(final HttpResponse response,
+final HttpContext context) {
+if (response == null) {
+throw new IllegalArgumentException
+("HTTP response may not be null.");
+}
+if (context == null) {
+throw new IllegalArgumentException
+("HTTP context may not be null.");
+}
+HttpConnection conn = (HttpConnection)
+context.getAttribute(ExecutionContext.HTTP_CONNECTION);
+if (conn != null && !conn.isOpen())
+return false;
+// do NOT check for stale connection, that is an expensive operation
+// Check for a self-terminating entity. If the end of the entity will
+// be indicated by closing the connection, there is no keep-alive.
+HttpEntity entity = response.getEntity();
+ProtocolVersion ver = response.getStatusLine().getProtocolVersion();
+if (entity != null) {
+if (entity.getContentLength() < 0) {
+if (!entity.isChunked() ||
+ver.lessEquals(HttpVersion.HTTP_1_0)) {
+// if the content length is not known and is not chunk
+// encoded, the connection cannot be reused
+return false;
+}
+}
+}
+// Check for the "Connection" header. If that is absent, check for
+// the "Proxy-Connection" header. The latter is an unspecified and
+// broken but unfortunately common extension of HTTP.
+HeaderIterator hit = response.headerIterator(HTTP.CONN_DIRECTIVE);
+if (!hit.hasNext())
+hit = response.headerIterator("Proxy-Connection");
+// Experimental usage of the "Connection" header in HTTP/1.0 is
+// documented in RFC 2068, section 19.7.1. A token "keep-alive" is
+// used to indicate that the connection should be persistent.
+// Note that the final specification of HTTP/1.1 in RFC 2616 does not
+// include this information. Neither is the "Connection" header
+// mentioned in RFC 1945, which informally describes HTTP/1.0.
+//
+// RFC 2616 specifies "close" as the only connection token with a
+// specific meaning: it disables persistent connections.
+//
+// The "Proxy-Connection" header is not formally specified anywhere,
+// but is commonly used to carry one token, "close" or "keep-alive".
+// The "Connection" header, on the other hand, is defined as a
+// sequence of tokens, where each token is a header name, and the
+// token "close" has the above-mentioned additional meaning.
+//
+// To get through this mess, we treat the "Proxy-Connection" header
+// in exactly the same way as the "Connection" header, but only if
+// the latter is missing. We scan the sequence of tokens for both
+// "close" and "keep-alive". As "close" is specified by RFC 2068,
+// it takes precedence and indicates a non-persistent connection.
+// If there is no "close" but a "keep-alive", we take the hint.
+if (hit.hasNext()) {
+try {
+TokenIterator ti = createTokenIterator(hit);
+boolean keepalive = false;
+while (ti.hasNext()) {
+final String token = ti.nextToken();
+if (HTTP.CONN_CLOSE.equalsIgnoreCase(token)) {
+return false;
+} else if (HTTP.CONN_KEEP_ALIVE.equalsIgnoreCase(token)) {
+// continue the loop, there may be a "close" afterwards
+keepalive = true;
+}
+}
+if (keepalive)
+return true;
+// neither "close" nor "keep-alive", use default policy
+} catch (ParseException px) {
+// invalid connection header means no persistent connection
+// we don't have logging in HttpCore, so the exception is lost
+return false;
+}
+}
+// default since HTTP/1.1 is persistent, before it was non-persistent
+return !ver.lessEquals(HttpVersion.HTTP_1_0);
+}
+/**
+* Creates a token iterator from a header iterator.
+* This method can be overridden to replace the implementation of
+* the token iterator.
+*
+* @param hit       the header iterator
+*
+* @return  the token iterator
+*/
+protected TokenIterator createTokenIterator(HeaderIterator hit) {
+return new BasicTokenIterator(hit);
+}
+}

The Tor Browser / file comparison

comparison: mobile/android/thirdparty/ch/boye/httpclientandroidlib/impl/DefaultConnectionReuseStrategy.java

mobile/android/thirdparty/ch/boye/httpclientandroidlib/impl/DefaultConnectionReuseStrategy.java